Elihu thomson



(No Model.

B. THOMSON.

ELECTRIC ARC LAMP.

No. 258,684. Patented May 80, 1882.

ventions in that the carbon-adjusting magnet UNITED STATES PATENT OFFICE.

ELIHU THOMSON, OF NEW BRITAIN, CONNECTICUT, ASSIGNOR TO THE AMERICAN ELECTRIC COMPANY, OF SAME PLACE.

ELECTRIC-A RC LAMP.

SPECIFICATION forming part of Letters Patent No. 258,684, dated May 30, 1882.

Application filed J nly 11, 1881.

To all whom it may concern:

Be it known that I, ELIHU THOMSON, a citizen of the United States, residing in New Britain, county of Hartford, State of Connecticut, have invented certain new and useful Improvements in Electric-Arc Lam ps, of which the following is a specification. My invention relates to electric lamps designed to be placed upon a circuit in series, and in which the electro-rnotive force of the generators supplying said circuit is sustained, whether the circuit be closed or open, through the lamp-carbons. It is therefore adapted to be run by generators the field-magnets of which are excited by separate currents from those traversing the lamp itself, or by generators the field of which is not dependent on the reaction of the current supplying the lamps, or by batteries and thermoelectric generators where the electro-motive force is sustained whether the circuit be open or closed.

Briefly, my invention comprises the combination of devices controlling the position of the carbon pencils and arranged to mechanically separate said carbons to a sma l interval; an electro-magnet fed by any suitable current from any source, the action of which upon a core or armature causes the approach and feeding of the carbons toward one another, and a shunt or derived circuit magnet around the arc controlling the admission of current to the magnet, by which the feeding mechanism is operated in such manner that when said derived-circuit magnet is strengthened by the fact of an elongated are between the carbons it shall attract an armature which actuates a pair of contacts by which current is admitted to the other electro-magnet and the carbons caused to approach or feed together thereby.

My present invention difi'ers from former inis energized when the carbons are to be fed, and receives no currentuntil the arc has lengthened sufliciently, instead of the carbon-adjusting magnet being cut out or weakened when the feed is to take place.

Figure 1 shows aregulating mechanism constructed in accordance with my invention; Fig. 2, a modification 0f circuit-connections; Fig. 3, a further modification of said connec- (No model.)

tions; Fig. 4, an outline view of the relations of circuits as in Fig. 1; Fig.5, a form of (lashpot used in my invention for checking sudden movements of the parts.

It will be understood that any well-known mechanism can be used for the adjustment of the carbons which can be placed under the control of an electro-magnet for effecting the approach of the carbons, called feeding, and in which the separation is effected in any suitable manner, as by a spring or weight acting to open the carbon are.

In Fig. l, R It is a rod supporting the electrode of carbon E, and by which it is held opposite the other carbon, E. A clamp, C, is arranged to seize said rod, and said clamp is lifted by the agency of a spring, S, acting upon a lever, B, pivoted at Q, by which the clamp C is supported. The lever B is provided with a dash-pot or check, P.

The clamp C is preferably provided with a movable jaw, 13, with elongation t, by which the rod R is gripped, as fully described in prior applicationsforLettersPatent, the spring Z acting to hold the jaw t t in place. The clamp C is opened by the lowering of the armature when attracted by the magnet lWI when it is energized by a current. The clamp opens by the part it coming into contact with a stop, 1, when said clamp is so depressed or lowered.

The electro-magnet M, which, as stated, acts to open the clamp by attracting its armature B against the spring 8, is either placed in circuit with the carbons, as in Figs. 1 and 4, or in a separate circuit, as in Fig. 2, or in a derived circuit around the arc, as in Fig. 3. In either case the said magnet is provided with a set of open-circuiting or shunting contacts, a I), the closing or opening of which controls the presence or absence of current in the coils of the magnet M.

An clectro-magnct, K, Figs. 1,2, 3, 4, is placed in a derived circuit around the carbons E E and the arc, and adjusted so as to attract the armature A and move the contacts a b to admit the current to the magnet M when the power of said magnet K has increased, due to a lengthening of the arc. The proper adjustment is easily efi'ected by providing the armatureA with a retracting-springer with weights W, serving the same purpose. It is preferable, also, to give the magnet-poles of K atapered form and provide a corresponding opening in its armature A, to secure uniformity of attraction in various positions of said armature, as described in prior applications for Letters Patent.

As shown in Figs. 1 and 4, the current enters at X, passes to contact I), to the magnet M, thence to the rod It, Fig. 4, branched to the other contact, a, Fig. 4, passes the carbons at E E, and out at Y. The shunt branch through K is, as usual, any connection around the are. When the contacts at a b are closed the magnet M is shunted, and is momentarily energized when the said contacts are open ed by the increased power of K, and the armature B being then attracted, the clamp 0 opened in consequence, a downward movement of the rod It takes place and the carbon E is fed. This action is repeated as often as necessary.

The carbons E E, on starting, require to be thrust together to establish the are, after which the lamp is self-adjustin g. This putting together ofthe carbons is not needed in modifications shown in Figs. 2 and 3.

The magnet M is in Fig. 2 not placed in the main circuit with the carbons; but it and the contacts a b are traversed by a separate current from any source. The action is the same in principle as in Fig. 1.

In Fig. 3 the magnet M is put in a derived circuit around the carbon are by the closing of the contacts a b by the action of the shuntmagnet K, as before. In this latter case the magnet M is of high resistance and the spark at the opening of the contacts a I) very feeble.

In Fig. l the armature A is provided with a projection, D, so that when the are E E has increased to an abnormal extent, resulting in greatly-increased strength of the shunt-magnet K, thejaw t t is opened by the projection D lifted by the armature A, owing to said increased strength ofK. This latter action only takes place when the magnet M fails to effect a feeding of the carbons.

When the carbons are consumed to a sufficient extent it is desirable that they be no lon gcr allowed to produce an are between them but that they should fall together and maintain a closed circuit. This I accomplish by placing a projection or button, F, at a suitable point upon the rod 1%, which, when the rod R descends, shall come into contact with a lever, L, to which the stop I is hun When the but ton Fstrilies the lever L the stop I is raised, at the same time raising the toe or jawt it, so as to free the clamp G from the rod R. The rod B, being thus relieved of the supporting action of the clamp (J, descends so as to close thearc at E E, the lever L having a sufficient range of movement to allow free descent-of the rod It even after the button F has struck the leverL.

The dash-pot check P, Fi .1, may be a cylinder fitted with a long plunger and containing only air, as often employed as a check upon sudden movements; but where aliquid-as oil or glycerineis used, difficulty arises from the spilling of fluid should the lamp be in verted or placed considerably out of the vertical. Such difliculty I completely avoid by constructing the dash-pot as shown in Fig. 5.

The body or cylinder 1 is provided in its interior with an inverted tubular neck, Gr, and at its top with a recurved cap, J.

The piston H is placed in the fluid in the lower compartment, and its rod 9 has an inverted cup, I, attached and hung in the upper compartment between the cap J and the neck or partition G. In the inverted position the cup Iis seat-ed as a valve upon the inner edges of the cap J, and the piston 11 covers the opening in the part Gr. The device may be turned into any position or moved rapidly without the escape of its liquid contents, which in quart tity are sufficient to just cover the piston H.

I claim- 1. The combination, with the clamp or clutch in an electric lamp, a feed-operating electromagnet normally out of circuit, and a retractor acting in opposition to said electromagnetfor holding the clampin position, where it will engage with and prevent the carbon rod from feeding, of a derived-circuit electromagnet, a circuit-closer and breaker operated thereby, and circuit-connections arranged in the manner described, whereby when the derived-circuit magnet is strengthened, owing to an increase in the length of are, an electric current is admitted to the feed-operating electro-magnet and energizes the same for the purpose of producing a feed of the carbon.

2. The combination, with the feed-regulating mechanism in an electric lamp, an electro magnetfor releasing said feed mechanism, and a retractor acting in opposition to said electromagnet to hold the feed mechanism out of action, of a derived-circuit electro-magnet, a circuit-closer, and connections, substantially as described, whereby when the power of the derived-circuit electro-magnet is increased an electric current may be admitted to the electromagnet of the feed-regulating mechanism, so as to energize the same and cause the feeding of the electrode.

3. The combination, with the carbon rod or carrier in an electric lamp, of a clutch or clamp and spring for normally holding said clamp in engagement with the rod or carrier, an electromagnet for releasing the clutch from the rod or carrier, a derived-circuit electro-magnet, and a circuit-closer, and connections, as described, for admitting an electric current to the releasing electro'magnet when the power of the derived-circuit electro magnet increases.

4. The combination, with the feed-regulatin g clutch or clamp for the carbon rod or carrier, of means for releasing the clamp, and a lug, toe, or projection upon the carbon rod, arranged as described, to come into contact with and actuate the releasing devices.

5. The combination, substantially as described, with the spring-actuated clampingtoe, of mechanism engaging with the toe so 8. The combination, with an electric lamp,

as to disengage it from the carbon-carrier, and of a dash-pot having a division, G, and curved a lug-or projection upon the carbon-carrier. cap J, combined, in the manner shown and r5 6. The c0mbination,withthe carbon-support described, with the piston H, rod 7, and in- 5 and its lug F, of lever L, stop 1, and clampverted cup I.

jaw t t, substantially as and for the purpose described. I ELIHU THOMSON.

7. The combination, with an electric lamp,

of a dash-pot having division G placed with Witnesses:

f 10 its opening immediately above the piston, so E. WILBUR RICE F that the latter acts as avalve when the cup is EDWIN J. HOUSTON.

inverted. 

